The finite-element method is used to evaluate the effect of soil-structure interaction on the seismic response of embedded structural systems. The system considered is representative of a nuclear power station located on a multilayered, elastic medium. Effects of structure stiffness, rock motions, and soil properties are considered. Results are presented in terms of foundation acceleration spectra.
Results show that the inclusion of soil-structure interaction can amplify the free-field spectrum in certain frequency ranges while suppressing it in others. It is suggested that an uncoupled soil-structure model together with a rocking spring and a modified design spectrum be used to evaluate the seismic design requirements of nuclear power stations located on various soil sites.